Abstract: A pipette tip configured to fit on a mounting shaft that includes outwardly circumferentially extending locking lobes over which the pipette tip collar is mounted. When the pipette tip is fully mounted on the mounting shaft, a locking ring on the inside surface of the tip collar engages the lobes to provide an over-center engagement. The pipette tip includes a circular cantilever sealing ring that seals laterally against the mounting shaft when the tip is fully mounted. The circular cantilever sealing ring has an annular wall surrounded by a gap. The annular wall has an inside surface that slants inward to provide a lateral interference fit with the mounting shaft. The annular wall bends radially outward towards the gap, rather than stretch, when the tip is mounted on the mounting shaft thereby reducing require insertion force.

Abstract: A pipette tip rack system includes a disposable refill pack and a reusable base. After use, the disposable refill pack can be disassembled, and the components can be stacked or nested for space saving storage prior to disposal or recycling. The pipette tips in the disposable refill pack are configured to fit on a mounting shaft that includes outwardly circumferentially extending locking lobes over which the pipette tip collar is mounted. The pipette tip includes a circular cantilever sealing ring that seals laterally against the mounting shaft when the tip is fully mounted. The circular cantilever sealing ring has an annular wall surrounded by a gap. The annular wall has an inside surface that slants inward to provide a lateral interference fit with the mounting shaft. The annular wall bends radially outward towards the gap, rather than stretching, when the tip is mounted on the mounting shaft thereby reducing require insertion force.